Tat conjugation of adenovirus vector broadens tropism and enhances transduction efficiency.
OBJECTIVE
Adenovirus vectors (Advs) have been very useful for basic research and clinical gene therapy because they propagate to high titers and efficiently transduce cells and tissues regardless of the mitotic status. However, poor transduction of cells that lack the coxsackievirus and adenovirus receptor (CAR), the primary receptor for Advs, has limited Adv application. In this study, we attempted to generate novel Tat-Advs (Advs conjugated with the HIV Tat-derived peptide, a protein-transduction domain (PTD)) to broaden Adv tropism and enhance transduction efficiency.


METHODS
We constructed Tat-Advs by chemically conjugating Tat peptide to the surface-exposed lysine residues on Advs. We compared the gene transfer activity of Tat-Advs with that of unmodified Advs by measuring the luciferase expression in several types of cell lines.


RESULTS
Tat-Advs showed gene expression 1 to 3 log orders higher than unmodified Advs in CAR-negative adherent cells and blood cells, which are refractory to conventional Advs. The inhibition of Tat-Adv-mediated gene expression by heparin and macropinocytosis inhibitor confirms that binding of Tat-Adv to cellular HSPGs and macropinocytosis are essential for efficient CAR-independent transduction. We also demonstrated that Adv modified with another PTD (R8) had the same high transduction efficiency as Tat-Adv.


CONCLUSIONS
These data suggest that Tat-Advs are important tools for transducing cells and will be useful as platform vectors for gene therapy.
Yoshioka
Yasuo
Y
The center for Advanced Medical Engineering and Informatics, Osaka University, 1-6, Yamadaoka, Suita, Osaka, 565-0871, Japan. yasuo@phs.osaka-u.ac.jp
Asavatanabodee
Ratima
R
Eto
Yusuke
Y
Watanabe
Hikaru
H
Morishige
Tomohiro
T
Yao
Xinglei
X
Kida
Shinya
S
Maeda
Mitsuko
M
Mukai
Yohei
Y
Mizuguchi
Hiroyuki
H
Kawasaki
Koichi
K
Okada
Naoki
N
Nakagawa
Shinsaku
S
D000256:Adenoviridae / Q000235:genetics*; D001773:Blood Cells / Q000821:virology; D002448:Cell Adhesion / Q000235:genetics; D045744:Cell Line, Tumor; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics*; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D009500:Neutralization Tests; D010873:Pinocytosis / Q000235:genetics; D011991:Receptors, Virus / Q000235:genetics; D014161:Transduction, Genetic / Q000379:methods*; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000235:genetics*
D011991:Receptors, Virus; D054322:tat Gene Products, Human Immunodeficiency Virus; D006493:Heparin